A conventional thermal recording material comprises a support material made of, for example, a sheet of ordinary paper, synthetic paper, or a resin film, and a thermal recording layer, formed on the support material, on which images can be formed by application of heat thereto. Because of the capability of forming images by simple application of heat, such thermal recording materials are widely used with thermal printers for recording output information from computers, facsimile apparatus, telex, cash receipts, cash registers, and other information transmission and measuring instruments. Furthermore, such thermal recording materials are employed as adhesive labels as an identification device which is intended to be provided to the institution or business utilizing the device in such a manner that it may ultimately be imprinted with a bar code or other variable information which will identify the person or object to whom the identification device is applied.